The lever corkscrew (also known as a “waiter's friend”) having a double fulcrum, such as that described in the document EP 0 041 026, is a corkscrew composed of a handle on which is articulated a worm and a lever preformed with two notches forming two fulcra permitting the effortless extraction of corks in two steps.
One embodiment of this corkscrew proposes one single lever with two notches preformed in this latter. This embodiment has the drawback that as the first fulcrum or notch is not retractable, this latter being used first abuts the cork when the second fulcrum or notch is to be used.
Another embodiment proposes two separate levers articulated in a case on one and the same pin secured to the handle, a small lever including the notch corresponding to the fulcrum of the first step retracting within a larger lever intended for the second step. Nevertheless, the course of the small lever outside the first one is not controlled, requiring a certain amount of practice in order for this embodiment to be used effectively.
More recently, a double lever with a first retractable fulcrum has been proposed in the document FR 2873108. The corkscrew described in this document comprises two separate levers articulated in a case on one and the same pin secured to the handle, the small lever including the notch corresponding to the fulcrum of the first step retracting within a larger lever intended for the second step. A spring provided on the articulation retains the first lever in a retracted position within the second lever, in the absence of pressure from the user. A tab joined to the small lever co-operates with parts joined to the second lever in order to limit the rotation of the small lever within the large lever.
This lever has the drawback that it necessitates a spring in order to retract the first lever within the second one which adds to the cost of this corkscrew.
Another drawback noted by the applicant relates to the manipulation of the folding blade conventionally integrated into the handle and articulated on the same pin as the levers. This blade is extended before use of the worm, for the purpose of cutting the material covering the neck in order to give access to the cork. Once the cork is accessible, this blade is folded back in the handle, the levers and the worm are extended and the worm is screwed into the cork. Because of its small size and stresses on its pivot pin, the extension and the folding of this blade are awkward operations.